Sorry to harp on this, because $1M is definitely a nice gesture, even from a guy who says he's worth $8B (and let's put it in terms most of us can better understand: percentage wise it works out to a guy worth $50K giving $6.25, which, again, still a nice gesture).
But look at the WaPo article I quoted from. Just because Trump says he's pledging $1M of his own money is no reason to believe he'll be parting with $1M of his own money. Maybe he will, maybe he won't. It's strange how he's always so forthcoming about the pledging part, but secretive about the actual giving part.